text: /*
  -----------------------------------------------------------------------------
  This source file is part of OGRE
  (Object-oriented Graphics Rendering Engine)
  For the latest info, see http://www.ogre3d.org/
  
  Copyright (c) 2000-2014 Torus Knot Software Ltd
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
  -----------------------------------------------------------------------------
  */
  #include "OgreStableHeaders.h"
  #include "OgrePixelFormat.h"
  #include "OgrePixelFormatDescriptions.h"
  
  namespace {
  #include "OgrePixelConversions.h"
  }
  
  namespace Ogre {
  
      //-----------------------------------------------------------------------
      size_t PixelBox::getConsecutiveSize() const
      {
          return PixelUtil::getMemorySize(getWidth(), getHeight(), getDepth(), format);
      }
      PixelBox PixelBox::getSubVolume(const Box &def, bool resetOrigin /* = true */) const
      {
          OgreAssert(contains(def), "");
  
          if(PixelUtil::isCompressed(format) && (def.left != left || def.top != top || def.right != right || def.bottom != bottom))
              OGRE_EXCEPT(Exception::ERR_INVALIDPARAMS, "Cannot return subvolume of compressed PixelBuffer with less than slice granularity", "PixelBox::getSubVolume");
  
          // Calculate new pixelbox and optionally reset origin.
          PixelBox rval(def, format, data);
          rval.rowPitch = rowPitch;
          rval.slicePitch = slicePitch;
  
          if(resetOrigin)
          {
              if(PixelUtil::isCompressed(format))
              {
                  if(rval.front > 0)
                  {
                      rval.data = (uint8*)rval.data + rval.front * PixelUtil::getMemorySize(getWidth(), getHeight(), 1, format);
                      rval.back -= rval.front;
                      rval.front = 0;
                  }
              }
              else
              {
                  rval.data = rval.getTopLeftFrontPixelPtr();
                  rval.right -= rval.left;
                  rval.bottom -= rval.top;
                  rval.back -= rval.front;
                  rval.front = rval.top = rval.left = 0;
              }
          }
  
          return rval;
      }
      uchar* PixelBox::getTopLeftFrontPixelPtr() const
      {
          return data + (left + top * rowPitch + front * slicePitch) * PixelUtil::getNumElemBytes(format);
      }
      //-----------------------------------------------------------------------
      /**
      * Directly get the description record for provided pixel format. For debug builds,
      * this checks the bounds of fmt with an assertion.
      */
      static inline const PixelFormatDescription &getDescriptionFor(const PixelFormat fmt)
      {
          const int ord = (int)fmt;
          assert(ord>=0 && ord<PF_COUNT);
  
          return _pixelFormats[ord];
      }
      //-----------------------------------------------------------------------
      size_t PixelUtil::getNumElemBytes( PixelFormat format )
      {
          return getDescriptionFor(format).elemBytes;
      }
      //-----------------------------------------------------------------------
      static size_t astc_slice_size(uint32 width, uint32 height, uint32 blockWidth, uint32 blockHeight)
      {
          return ((width + blockWidth - 1) / blockWidth) *
                 ((height + blockHeight - 1) / blockHeight) * 16;
      }
      size_t PixelUtil::getMemorySize(uint32 width, uint32 height, uint32 depth, PixelFormat format)
      {
          if(isCompressed(format))
          {
              switch(format)
              {
                  // DXT formats work by dividing the image into 4x4 blocks, then encoding each
                  // 4x4 block with a certain number of bytes. 
                  case PF_DXT1:
                      return ((width+3)/4)*((height+3)/4)*8 * depth;
                  case PF_DXT2:
                  case PF_DXT3:
                  case PF_DXT4:
                  case PF_DXT5:
                      return ((width+3)/4)*((height+3)/4)*16 * depth;
                  case PF_BC4_SNORM:
                  case PF_BC4_UNORM:
                      return ((width+3)/4)*((height+3)/4)*8 * depth;
                  case PF_BC5_SNORM:
                  case PF_BC5_UNORM:
                  case PF_BC6H_SF16:
                  case PF_BC6H_UF16:
                  case PF_BC7_UNORM:
                      return ((width+3)/4)*((height+3)/4)*16 * depth;
  
                  // Size calculations from the PVRTC OpenGL extension spec
                  // http://www.khronos.org/registry/gles/extensions/IMG/IMG_texture_compression_pvrtc.txt
                  // Basically, 32 bytes is the minimum texture size.  Smaller textures are padded up to 32 bytes
                  case PF_PVRTC_RGB2:
                  case PF_PVRTC_RGBA2:
                  case PF_PVRTC2_2BPP:
                      return (std::max((int)width, 16) * std::max((int)height, 8) * 2 + 7) / 8;
                  case PF_PVRTC_RGB4:
                  case PF_PVRTC_RGBA4:
                  case PF_PVRTC2_4BPP:
                      return (std::max((int)width, 8) * std::max((int)height, 8) * 4 + 7) / 8;
  
                  // Size calculations from the ETC spec
                  // https://www.khronos.org/registry/OpenGL/extensions/OES/OES_compressed_ETC1_RGB8_texture.txt
                  case PF_ETC1_RGB8:
                  case PF_ETC2_RGB8:
                  case PF_ETC2_RGBA8:
                  case PF_ETC2_RGB8A1:
                      return ((width + 3) / 4) * ((height + 3) / 4) * 8;
  
                  case PF_ATC_RGB:
                      return ((width + 3) / 4) * ((height + 3) / 4) * 8;
                  case PF_ATC_RGBA_EXPLICIT_ALPHA:
                  case PF_ATC_RGBA_INTERPOLATED_ALPHA:
                      return ((width + 3) / 4) * ((height + 3) / 4) * 16;
  
                  case PF_ASTC_RGBA_4X4_LDR:
                      return astc_slice_size(width, height, 4, 4) * depth;
                  case PF_ASTC_RGBA_5X4_LDR:
                      return astc_slice_size(width, height, 5, 4) * depth;
                  case PF_ASTC_RGBA_5X5_LDR:
                      return astc_slice_size(width, height, 5, 5) * depth;
                  case PF_ASTC_RGBA_6X5_LDR:
                      return astc_slice_size(width, height, 6, 5) * depth;
                  case PF_ASTC_RGBA_6X6_LDR:
                      return astc_slice_size(width, height, 6, 6) * depth;
                  case PF_ASTC_RGBA_8X5_LDR:
                      return astc_slice_size(width, height, 8, 5) * depth;
                  case PF_ASTC_RGBA_8X6_LDR:
                      return astc_slice_size(width, height, 8, 6) * depth;
                  case PF_ASTC_RGBA_8X8_LDR:
                      return astc_slice_size(width, height, 8, 8) * depth;
                  case PF_ASTC_RGBA_10X5_LDR:
                      return astc_slice_size(width, height, 10, 5) * depth;
                  case PF_ASTC_RGBA_10X6_LDR:
                      return astc_slice_size(width, height, 10, 6) * depth;
                  case PF_ASTC_RGBA_10X8_LDR:
                      return astc_slice_size(width, height, 10, 8) * depth;
                  case PF_ASTC_RGBA_10X10_LDR:
                      return astc_slice_size(width, height, 10, 10) * depth;
                  case PF_ASTC_RGBA_12X10_LDR:
                      return astc_slice_size(width, height, 12, 10) * depth;
                  case PF_ASTC_RGBA_12X12_LDR:
                      return astc_slice_size(width, height, 12, 12) * depth;
                  default:
                  OGRE_EXCEPT(Exception::ERR_INVALIDPARAMS, "Invalid compressed pixel format",
                      "PixelUtil::getMemorySize");
              }
          }
          else
          {
              return width*height*depth*getNumElemBytes(format);
          }
      }
      //-----------------------------------------------------------------------
      size_t PixelUtil::getNumElemBits( PixelFormat format )
      {
          return getDescriptionFor(format).elemBytes * 8;
      }
      //-----------------------------------------------------------------------
      unsigned int PixelUtil::getFlags( PixelFormat format )
      {
          return getDescriptionFor(format).flags;
      }
      //-----------------------------------------------------------------------
      bool PixelUtil::hasAlpha(PixelFormat format)
      {
          return (PixelUtil::getFlags(format) & PFF_HASALPHA) > 0;
      }
      //-----------------------------------------------------------------------
      bool PixelUtil::isFloatingPoint(PixelFormat format)
      {
          return (PixelUtil::getFlags(format) & PFF_FLOAT) > 0;
      }
      //-----------------------------------------------------------------------
      bool PixelUtil::isInteger(PixelFormat format)
      {
          return (PixelUtil::getFlags(format) & PFF_INTEGER) > 0;
      }
      //-----------------------------------------------------------------------
      bool PixelUtil::isCompressed(PixelFormat format)
      {
          return (PixelUtil::getFlags(format) & PFF_COMPRESSED) > 0;
      }
      //-----------------------------------------------------------------------
      bool PixelUtil::isDepth(PixelFormat format)
      {
          return (PixelUtil::getFlags(format) & PFF_DEPTH) > 0;
      }
      //-----------------------------------------------------------------------
      bool PixelUtil::isNativeEndian(PixelFormat format)
      {
          return (PixelUtil::getFlags(format) & PFF_NATIVEENDIAN) > 0;
      }
      //-----------------------------------------------------------------------
      bool PixelUtil::isLuminance(PixelFormat format)
      {
          return (PixelUtil::getFlags(format) & PFF_LUMINANCE) > 0;
      }
      //-----------------------------------------------------------------------
      void PixelUtil::getBitDepths(PixelFormat format, int rgba[4])
      {
          const PixelFormatDescription &des = getDescriptionFor(format);
          rgba[0] = des.rbits;
          rgba[1] = des.gbits;
          rgba[2] = des.bbits;
          rgba[3] = des.abits;
      }
      //-----------------------------------------------------------------------
      void PixelUtil::getBitMasks(PixelFormat format, uint64 rgba[4])
      {
          const PixelFormatDescription &des = getDescriptionFor(format);
          rgba[0] = des.rmask;
          rgba[1] = des.gmask;
          rgba[2] = des.bmask;
          rgba[3] = des.amask;
      }
      //---------------------------------------------------------------------
      void PixelUtil::getBitShifts(PixelFormat format, unsigned char rgba[4])
      {
          const PixelFormatDescription &des = getDescriptionFor(format);
          rgba[0] = des.rshift;
          rgba[1] = des.gshift;
          rgba[2] = des.bshift;
          rgba[3] = des.ashift;
      }
      //-----------------------------------------------------------------------
      const String& PixelUtil::getFormatName(PixelFormat srcformat)
      {
          return getDescriptionFor(srcformat).name;
      }
      //-----------------------------------------------------------------------
      bool PixelUtil::isAccessible(PixelFormat srcformat)
      {
          return (srcformat != PF_UNKNOWN) && !isCompressed(srcformat);
      }
      //-----------------------------------------------------------------------
      PixelComponentType PixelUtil::getComponentType(PixelFormat fmt)
      {
          const PixelFormatDescription &des = getDescriptionFor(fmt);
          return des.componentType;
      }
      //-----------------------------------------------------------------------
      size_t PixelUtil::getComponentCount(PixelFormat fmt)
      {
          const PixelFormatDescription &des = getDescriptionFor(fmt);
          return des.componentCount;
      }
      //-----------------------------------------------------------------------
      PixelFormat PixelUtil::getFormatFromName(const String& name, bool accessibleOnly, bool caseSensitive)
      {
          String tmp = name;
          if (!caseSensitive)
          {
              // We are stored upper-case format names.
              StringUtil::toUpperCase(tmp);
          }
  
          for (int i = 0; i < PF_COUNT; ++i)
          {
              PixelFormat pf = static_cast<PixelFormat>(i);
              if (!accessibleOnly || isAccessible(pf))
              {
                  if (tmp == getFormatName(pf))
                      return pf;
              }
          }
  
          // allow look-up by alias name
          if(tmp == "PF_BYTE_RGB")
              return PF_BYTE_RGB;
          if(tmp == "PF_BYTE_RGBA")
              return PF_BYTE_RGBA;
          if(tmp == "PF_BYTE_BGR")
              return PF_BYTE_BGR;
          if(tmp == "PF_BYTE_BGRA")
              return PF_BYTE_BGRA;
  
          return PF_UNKNOWN;
      }
      //-----------------------------------------------------------------------
      PixelFormat PixelUtil::getFormatForBitDepths(PixelFormat fmt, ushort integerBits, ushort floatBits)
      {
          switch (integerBits)
          {
          case 16:
              switch (fmt)
              {
              case PF_R8G8B8:
              case PF_X8R8G8B8:
                  return PF_R5G6B5;
  
              case PF_B8G8R8:
              case PF_X8B8G8R8:
                  return PF_B5G6R5;
  
              case PF_A8R8G8B8:
              case PF_R8G8B8A8:
              case PF_A8B8G8R8:
              case PF_B8G8R8A8:
                  return PF_A4R4G4B4;
  
              case PF_A2R10G10B10:
              case PF_A2B10G10R10:
                  return PF_A1R5G5B5;
  
              default:
                  // use original image format
                  break;
              }
              break;
  
          case 32:
              switch (fmt)
              {
              case PF_R5G6B5:
                  return PF_X8R8G8B8;
  
              case PF_B5G6R5:
                  return PF_X8B8G8R8;
  
              case PF_A4R4G4B4:
                  return PF_A8R8G8B8;
  
              case PF_A1R5G5B5:
                  return PF_A2R10G10B10;
  
              default:
                  // use original image format
                  break;
              }
              break;
  
          default:
              // use original image format
              break;
          }
  
          switch (floatBits)
          {
          case 16:
              switch (fmt)
              {
              case PF_FLOAT32_R:
                  return PF_FLOAT16_R;
  
              case PF_FLOAT32_RGB:
                  return PF_FLOAT16_RGB;
  
              case PF_FLOAT32_RGBA:
                  return PF_FLOAT16_RGBA;
  
              default:
                  // use original image format
                  break;
              }
              break;
  
          case 32:
              switch (fmt)
              {
              case PF_FLOAT16_R:
                  return PF_FLOAT32_R;
  
              case PF_FLOAT16_RGB:
                  return PF_FLOAT32_RGB;
  
              case PF_FLOAT16_RGBA:
                  return PF_FLOAT32_RGBA;
  
              default:
                  // use original image format
                  break;
              }
              break;
  
          default:
              // use original image format
              break;
          }
  
          return fmt;
      }
      //-----------------------------------------------------------------------
      /*************************************************************************
      * Pixel packing/unpacking utilities
      */
      void PixelUtil::packColour(const uint8 r, const uint8 g, const uint8 b, const uint8 a, const PixelFormat pf,  void* dest)
      {
          const PixelFormatDescription &des = getDescriptionFor(pf);
          if(des.flags & PFF_NATIVEENDIAN) {
              // Shortcut for integer formats packing
              unsigned int value = ((Bitwise::fixedToFixed(r, 8, des.rbits)<<des.rshift) & des.rmask) |
                  ((Bitwise::fixedToFixed(g, 8, des.gbits)<<des.gshift) & des.gmask) |
                  ((Bitwise::fixedToFixed(b, 8, des.bbits)<<des.bshift) & des.bmask) |
                  ((Bitwise::fixedToFixed(a, 8, des.abits)<<des.ashift) & des.amask);
              // And write to memory
              Bitwise::intWrite(dest, des.elemBytes, value);
          } else {
              // Convert to float
              packColour((float)r/255.0f,(float)g/255.0f,(float)b/255.0f,(float)a/255.0f, pf, dest);
          }
      }
      //-----------------------------------------------------------------------
      void PixelUtil::packColour(const float r, const float g, const float b, const float a, const PixelFormat pf,  void* dest)
      {
          // Catch-it-all here
          const PixelFormatDescription &des = getDescriptionFor(pf);
          if(des.flags & PFF_NATIVEENDIAN) {
              // Do the packing
              //std::cerr << dest << " " << r << " " << g <<  " " << b << " " << a << std::endl;
              const unsigned int value = ((Bitwise::floatToFixed(r, des.rbits)<<des.rshift) & des.rmask) |
                  ((Bitwise::floatToFixed(g, des.gbits)<<des.gshift) & des.gmask) |
                  ((Bitwise::floatToFixed(b, des.bbits)<<des.bshift) & des.bmask) |
                  ((Bitwise::floatToFixed(a, des.abits)<<des.ashift) & des.amask);
              // And write to memory
              Bitwise::intWrite(dest, des.elemBytes, value);
          } else {
              switch(pf)
              {
              case PF_FLOAT32_R:
                  ((float*)dest)[0] = r;
                  break;
              case PF_FLOAT32_GR:
                  ((float*)dest)[0] = g;
                  ((float*)dest)[1] = r;
                  break;
              case PF_FLOAT32_RGB:
                  ((float*)dest)[0] = r;
                  ((float*)dest)[1] = g;
                  ((float*)dest)[2] = b;
                  break;
              case PF_FLOAT32_RGBA:
                  ((float*)dest)[0] = r;
                  ((float*)dest)[1] = g;
                  ((float*)dest)[2] = b;
                  ((float*)dest)[3] = a;
                  break;
              case PF_DEPTH16:
              case PF_FLOAT16_R:
                  ((uint16*)dest)[0] = Bitwise::floatToHalf(r);
                  break;
              case PF_FLOAT16_GR:
                  ((uint16*)dest)[0] = Bitwise::floatToHalf(g);
                  ((uint16*)dest)[1] = Bitwise::floatToHalf(r);
                  break;
              case PF_FLOAT16_RGB:
                  ((uint16*)dest)[0] = Bitwise::floatToHalf(r);
                  ((uint16*)dest)[1] = Bitwise::floatToHalf(g);
                  ((uint16*)dest)[2] = Bitwise::floatToHalf(b);
                  break;
              case PF_FLOAT16_RGBA:
                  ((uint16*)dest)[0] = Bitwise::floatToHalf(r);
                  ((uint16*)dest)[1] = Bitwise::floatToHalf(g);
                  ((uint16*)dest)[2] = Bitwise::floatToHalf(b);
                  ((uint16*)dest)[3] = Bitwise::floatToHalf(a);
                  break;
              case PF_SHORT_RGB:
                  ((uint16*)dest)[0] = (uint16)Bitwise::floatToFixed(r, 16);
                  ((uint16*)dest)[1] = (uint16)Bitwise::floatToFixed(g, 16);
                  ((uint16*)dest)[2] = (uint16)Bitwise::floatToFixed(b, 16);
                  break;
              case PF_SHORT_RGBA:
                  ((uint16*)dest)[0] = (uint16)Bitwise::floatToFixed(r, 16);
                  ((uint16*)dest)[1] = (uint16)Bitwise::floatToFixed(g, 16);
                  ((uint16*)dest)[2] = (uint16)Bitwise::floatToFixed(b, 16);
                  ((uint16*)dest)[3] = (uint16)Bitwise::floatToFixed(a, 16);
                  break;
              case PF_BYTE_LA:
                  ((uint8*)dest)[0] = (uint8)Bitwise::floatToFixed(r, 8);
                  ((uint8*)dest)[1] = (uint8)Bitwise::floatToFixed(a, 8);
                  break;
              case PF_A2B10G10R10:
              {
                  const uint16 ir = static_cast<uint16>( Math::saturate( r ) * 1023.0f + 0.5f );
                  const uint16 ig = static_cast<uint16>( Math::saturate( g ) * 1023.0f + 0.5f );
                  const uint16 ib = static_cast<uint16>( Math::saturate( b ) * 1023.0f + 0.5f );
                  const uint16 ia = static_cast<uint16>( Math::saturate( a ) * 3.0f + 0.5f );
  
                  ((uint32*)dest)[0] = (ia << 30u) | (ir << 20u) | (ig << 10u) | (ib);
                  break;
              }
              default:
                  // Not yet supported
                  OGRE_EXCEPT(
                      Exception::ERR_NOT_IMPLEMENTED,
                      "pack to "+getFormatName(pf)+" not implemented",
                      "PixelUtil::packColour");
                  break;
              }
          }
      }
      //-----------------------------------------------------------------------
      void PixelUtil::unpackColour(uint8 *r, uint8 *g, uint8 *b, uint8 *a, PixelFormat pf,  const void* src)
      {
          const PixelFormatDescription &des = getDescriptionFor(pf);
          if(des.flags & PFF_NATIVEENDIAN) {
              // Shortcut for integer formats unpacking
              const unsigned int value = Bitwise::intRead(src, des.elemBytes);
              if(des.flags & PFF_LUMINANCE)
              {
                  // Luminance format -- only rbits used
                  *r = *g = *b = (uint8)Bitwise::fixedToFixed(
                      (value & des.rmask)>>des.rshift, des.rbits, 8);
              }
              else
              {
                  *r = (uint8)Bitwise::fixedToFixed((value & des.rmask)>>des.rshift, des.rbits, 8);
                  *g = (uint8)Bitwise::fixedToFixed((value & des.gmask)>>des.gshift, des.gbits, 8);
                  *b = (uint8)Bitwise::fixedToFixed((value & des.bmask)>>des.bshift, des.bbits, 8);
              }
              if(des.flags & PFF_HASALPHA)
              {
                  *a = (uint8)Bitwise::fixedToFixed((value & des.amask)>>des.ashift, des.abits, 8);
              }
              else
              {
                  *a = 255; // No alpha, default a component to full
              }
          } else {
              // Do the operation with the more generic floating point
              float rr = 0, gg = 0, bb = 0, aa = 0;
              unpackColour(&rr,&gg,&bb,&aa, pf, src);
              *r = (uint8)Bitwise::floatToFixed(rr, 8);
              *g = (uint8)Bitwise::floatToFixed(gg, 8);
              *b = (uint8)Bitwise::floatToFixed(bb, 8);
              *a = (uint8)Bitwise::floatToFixed(aa, 8);
          }
      }
      //-----------------------------------------------------------------------
      void PixelUtil::unpackColour(float *r, float *g, float *b, float *a,
          PixelFormat pf,  const void* src)
      {
          const PixelFormatDescription &des = getDescriptionFor(pf);
          if(des.flags & PFF_NATIVEENDIAN) {
              // Shortcut for integer formats unpacking
              const unsigned int value = Bitwise::intRead(src, des.elemBytes);
              if(des.flags & PFF_LUMINANCE)
              {
                  // Luminance format -- only rbits used
                  *r = *g = *b = Bitwise::fixedToFloat(
                      (value & des.rmask)>>des.rshift, des.rbits);
              }
              else
              {
                  *r = Bitwise::fixedToFloat((value & des.rmask)>>des.rshift, des.rbits);
                  *g = Bitwise::fixedToFloat((value & des.gmask)>>des.gshift, des.gbits);
                  *b = Bitwise::fixedToFloat((value & des.bmask)>>des.bshift, des.bbits);
              }
              if(des.flags & PFF_HASALPHA)
              {
                  *a = Bitwise::fixedToFloat((value & des.amask)>>des.ashift, des.abits);
              }
              else
              {
                  *a = 1.0f; // No alpha, default a component to full
              }
          } else {
              switch(pf)
              {
              case PF_FLOAT32_R:
                  *r = *g = *b = ((const float*)src)[0];
                  *a = 1.0f;
                  break;
              case PF_FLOAT32_GR:
                  *g = ((const float*)src)[0];
                  *r = *b = ((const float*)src)[1];
                  *a = 1.0f;
                  break;
              case PF_FLOAT32_RGB:
                  *r = ((const float*)src)[0];
                  *g = ((const float*)src)[1];
                  *b = ((const float*)src)[2];
                  *a = 1.0f;
                  break;
              case PF_FLOAT32_RGBA:
                  *r = ((const float*)src)[0];
                  *g = ((const float*)src)[1];
                  *b = ((const float*)src)[2];
                  *a = ((const float*)src)[3];
                  break;
              case PF_FLOAT16_R:
                  *r = *g = *b = Bitwise::halfToFloat(((const uint16*)src)[0]);
                  *a = 1.0f;
                  break;
              case PF_FLOAT16_GR:
                  *g = Bitwise::halfToFloat(((const uint16*)src)[0]);
                  *r = *b = Bitwise::halfToFloat(((const uint16*)src)[1]);
                  *a = 1.0f;
                  break;
              case PF_FLOAT16_RGB:
                  *r = Bitwise::halfToFloat(((const uint16*)src)[0]);
                  *g = Bitwise::halfToFloat(((const uint16*)src)[1]);
                  *b = Bitwise::halfToFloat(((const uint16*)src)[2]);
                  *a = 1.0f;
                  break;
              case PF_FLOAT16_RGBA:
                  *r = Bitwise::halfToFloat(((const uint16*)src)[0]);
                  *g = Bitwise::halfToFloat(((const uint16*)src)[1]);
                  *b = Bitwise::halfToFloat(((const uint16*)src)[2]);
                  *a = Bitwise::halfToFloat(((const uint16*)src)[3]);
                  break;
              case PF_SHORT_RGB:
                  *r = Bitwise::fixedToFloat(((const uint16*)src)[0], 16);
                  *g = Bitwise::fixedToFloat(((const uint16*)src)[1], 16);
                  *b = Bitwise::fixedToFloat(((const uint16*)src)[2], 16);
                  *a = 1.0f;
                  break;
              case PF_SHORT_RGBA:
                  *r = Bitwise::fixedToFloat(((const uint16*)src)[0], 16);
                  *g = Bitwise::fixedToFloat(((const uint16*)src)[1], 16);
                  *b = Bitwise::fixedToFloat(((const uint16*)src)[2], 16);
                  *a = Bitwise::fixedToFloat(((const uint16*)src)[3], 16);
                  break;
              case PF_BYTE_LA:
                  *r = *g = *b = Bitwise::fixedToFloat(((const uint8*)src)[0], 8);
                  *a = Bitwise::fixedToFloat(((const uint8*)src)[1], 8);
                  break;
              default:
                  // Not yet supported
                  OGRE_EXCEPT(Exception::ERR_NOT_IMPLEMENTED,
                      "unpack from "+getFormatName(pf)+" not implemented",
                      "PixelUtil::unpackColour");
                  break;
              }
          }
      }
      //-----------------------------------------------------------------------
      /* Convert pixels from one format to another */
      void PixelUtil::bulkPixelConversion(const PixelBox &src, const PixelBox &dst)
      {
          OgreAssert(src.getSize() == dst.getSize(), "");
  
          // Check for compressed formats, we don't support decompression, compression or recoding
          if(PixelUtil::isCompressed(src.format) || PixelUtil::isCompressed(dst.format))
          {
              if(src.format == dst.format && src.isConsecutive() && dst.isConsecutive())
              {
                  // we can copy with slice granularity, useful for Tex2DArray handling
                  size_t bytesPerSlice = getMemorySize(src.getWidth(), src.getHeight(), 1, src.format);
                  memcpy(dst.data + bytesPerSlice * dst.front,
                      src.data + bytesPerSlice * src.front,
                      bytesPerSlice * src.getDepth());
                  return;
              }
              else
              {
                  OGRE_EXCEPT(Exception::ERR_NOT_IMPLEMENTED,
                      "This method can not be used to compress or decompress images",
                      "PixelUtil::bulkPixelConversion");
              }
          }
  
          // The easy case
          if(src.format == dst.format) {
              // Everything consecutive?
              if(src.isConsecutive() && dst.isConsecutive())
              {
                  memcpy(dst.getTopLeftFrontPixelPtr(), src.getTopLeftFrontPixelPtr(), src.getConsecutiveSize());
                  return;
              }
  
              const size_t srcPixelSize = PixelUtil::getNumElemBytes(src.format);
              const size_t dstPixelSize = PixelUtil::getNumElemBytes(dst.format);
              uint8 *srcptr = src.data
                  + (src.left + src.top * src.rowPitch + src.front * src.slicePitch) * srcPixelSize;
              uint8 *dstptr = dst.data
                  + (dst.left + dst.top * dst.rowPitch + dst.front * dst.slicePitch) * dstPixelSize;
  
              // Calculate pitches+skips in bytes
              const size_t srcRowPitchBytes = src.rowPitch*srcPixelSize;
              //const size_t srcRowSkipBytes = src.getRowSkip()*srcPixelSize;
              const size_t srcSliceSkipBytes = src.getSliceSkip()*srcPixelSize;
  
              const size_t dstRowPitchBytes = dst.rowPitch*dstPixelSize;
              //const size_t dstRowSkipBytes = dst.getRowSkip()*dstPixelSize;
              const size_t dstSliceSkipBytes = dst.getSliceSkip()*dstPixelSize;
  
              // Otherwise, copy per row
              const size_t rowSize = src.getWidth()*srcPixelSize;
              for(size_t z=src.front; z<src.back; z++)
              {
                  for(size_t y=src.top; y<src.bottom; y++)
                  {
                      memcpy(dstptr, srcptr, rowSize);
                      srcptr += srcRowPitchBytes;
                      dstptr += dstRowPitchBytes;
                  }
                  srcptr += srcSliceSkipBytes;
                  dstptr += dstSliceSkipBytes;
              }
              return;
          }
          // Converting to PF_X8R8G8B8 is exactly the same as converting to
          // PF_A8R8G8B8. (same with PF_X8B8G8R8 and PF_A8B8G8R8)
          if(dst.format == PF_X8R8G8B8 || dst.format == PF_X8B8G8R8)
          {
              // Do the same conversion, with PF_A8R8G8B8, which has a lot of
              // optimized conversions
              PixelBox tempdst = dst;
              tempdst.format = dst.format==PF_X8R8G8B8?PF_A8R8G8B8:PF_A8B8G8R8;
              bulkPixelConversion(src, tempdst);
              return;
          }
          // Converting from PF_X8R8G8B8 is exactly the same as converting from
          // PF_A8R8G8B8, given that the destination format does not have alpha.
          if((src.format == PF_X8R8G8B8||src.format == PF_X8B8G8R8) && !hasAlpha(dst.format))
          {
              // Do the same conversion, with PF_A8R8G8B8, which has a lot of
              // optimized conversions
              PixelBox tempsrc = src;
              tempsrc.format = src.format==PF_X8R8G8B8?PF_A8R8G8B8:PF_A8B8G8R8;
              bulkPixelConversion(tempsrc, dst);
              return;
          }
  
  // NB VC6 can't handle the templates required for optimised conversion, tough
  #if OGRE_COMPILER != OGRE_COMPILER_MSVC || OGRE_COMP_VER >= 1300
          // Is there a specialized, inlined, conversion?
          if(doOptimizedConversion(src, dst))
          {
              // If so, good
              return;
          }
  #endif
  
          const size_t srcPixelSize = PixelUtil::getNumElemBytes(src.format);
          const size_t dstPixelSize = PixelUtil::getNumElemBytes(dst.format);
          uint8 *srcptr = src.data
              + (src.left + src.top * src.rowPitch + src.front * src.slicePitch) * srcPixelSize;
          uint8 *dstptr = dst.data
              + (dst.left + dst.top * dst.rowPitch + dst.front * dst.slicePitch) * dstPixelSize;
          
          // Old way, not taking into account box dimensions
          //uint8 *srcptr = static_cast<uint8*>(src.data), *dstptr = static_cast<uint8*>(dst.data);
  
          // Calculate pitches+skips in bytes
          const size_t srcRowSkipBytes = src.getRowSkip()*srcPixelSize;
          const size_t srcSliceSkipBytes = src.getSliceSkip()*srcPixelSize;
          const size_t dstRowSkipBytes = dst.getRowSkip()*dstPixelSize;
          const size_t dstSliceSkipBytes = dst.getSliceSkip()*dstPixelSize;
  
          // The brute force fallback
          float r = 0, g = 0, b = 0, a = 1;
          for(size_t z=src.front; z<src.back; z++)
          {
              for(size_t y=src.top; y<src.bottom; y++)
              {
                  for(size_t x=src.left; x<src.right; x++)
                  {
                      unpackColour(&r, &g, &b, &a, src.format, srcptr);
                      packColour(r, g, b, a, dst.format, dstptr);
                      srcptr += srcPixelSize;
                      dstptr += dstPixelSize;
                  }
                  srcptr += srcRowSkipBytes;
                  dstptr += dstRowSkipBytes;
              }
              srcptr += srcSliceSkipBytes;
              dstptr += dstSliceSkipBytes;
          }
      }
      //-----------------------------------------------------------------------
      void PixelUtil::bulkPixelVerticalFlip(const PixelBox &box)
      {
          // Check for compressed formats, we don't support decompression, compression or recoding
          if(PixelUtil::isCompressed(box.format))
          {
              OGRE_EXCEPT(Exception::ERR_NOT_IMPLEMENTED,
                          "This method can not be used for compressed formats",
                          "PixelUtil::bulkPixelVerticalFlip");
          }
          
          const size_t pixelSize = PixelUtil::getNumElemBytes(box.format);
          const size_t copySize = (box.right - box.left) * pixelSize;
  
          // Calculate pitches in bytes
          const size_t rowPitchBytes = box.rowPitch * pixelSize;
          const size_t slicePitchBytes = box.slicePitch * pixelSize;
  
          uint8 *basesrcptr = box.data
              + (box.left + box.top * box.rowPitch + box.front * box.slicePitch) * pixelSize;
          uint8 *basedstptr = basesrcptr + (box.bottom - box.top - 1) * rowPitchBytes;
          uint8* tmpptr = (uint8*)OGRE_MALLOC_SIMD(copySize, MEMCATEGORY_GENERAL);
          
          // swap rows
          const size_t halfRowCount = (box.bottom - box.top) >> 1;
          for(size_t z = box.front; z < box.back; z++)
          {
              uint8* srcptr = basesrcptr;
              uint8* dstptr = basedstptr;
              for(size_t y = 0; y < halfRowCount; y++)
              {
                  // swap rows
                  memcpy(tmpptr, dstptr, copySize);
                  memcpy(dstptr, srcptr, copySize);
                  memcpy(srcptr, tmpptr, copySize);
                  srcptr += rowPitchBytes;
                  dstptr -= rowPitchBytes;
              }
              basesrcptr += slicePitchBytes;
              basedstptr += slicePitchBytes;
          }
          
          OGRE_FREE_SIMD(tmpptr, MEMCATEGORY_GENERAL);
      }
  
      ColourValue PixelBox::getColourAt(size_t x, size_t y, size_t z) const
      {
          ColourValue cv;
  
          size_t pixelSize = PixelUtil::getNumElemBytes(format);
          size_t pixelOffset = pixelSize * (z * slicePitch + y * rowPitch + x);
          PixelUtil::unpackColour(&cv, format, (unsigned char *)data + pixelOffset);
  
          return cv;
      }
  
      void PixelBox::setColourAt(ColourValue const &cv, size_t x, size_t y, size_t z)
      {
          size_t pixelSize = PixelUtil::getNumElemBytes(format);
          size_t pixelOffset = pixelSize * (z * slicePitch + y * rowPitch + x);
          PixelUtil::packColour(cv, format, (unsigned char *)data + pixelOffset);
      }
  
  }
  